Pijanowska Joanna
Max-Planck Institut für Limnologie, Postfach 165, D-24306 Plön, Germany, , , , , , DE.
Oecologia. 1997 Sep;112(1):12-16. doi: 10.1007/s004420050277.
Daphnia magna can respond to chemical cues from freshly crushed conspecifics with various behavioural reactions. A shift in vertical distribution towards the bottom, the formation of aggregations and direct escape responses can all be induced by water-borne signals released from crushed Daphnia. The pattern and strength of the first two behavioural responses (i.e. the persistent tendency to occupy deeper strata in the experimental columns and to stay within patches) indicate that Daphnia perceive the signal from crushed conspecifics as nonspecific information, not necessarily associated with any particular kind of danger from either vertebrate or invertebrate predators. The adaptive value and possible costs associated with performing these two behavioural reactions are discussed. The adaptive value of the induced escape response was directly tested: Daphnia which had experienced the presence of a cue from crushed conspecifics avoided attacks by common bream more efficiently than naive Daphnia. The recognition of the signal originating from crushed conspecifics can be especially adaptive in encounters with unfamiliar predators and with predators that undergo ontogenetic shifts in their diet. Under natural conditions, the combination of such a signal with a predator cue can, very reliably, advertise the local scale of the predatory impact.
大型溞能够通过各种行为反应对新鲜碾碎的同种个体释放的化学信号做出响应。垂直分布向底部转移、形成聚集以及直接逃避反应都可由碾碎的大型溞释放的水溶性信号诱导产生。前两种行为反应的模式和强度（即在实验柱中持续倾向于占据更深水层以及待在斑块内）表明，大型溞将来自碾碎同种个体的信号视为非特异性信息，不一定与来自脊椎动物或无脊椎动物捕食者的任何特定危险相关。文中讨论了执行这两种行为反应的适应性价值以及可能的代价。对诱导产生的逃避反应的适应性价值进行了直接测试：经历过碾碎同种个体信号的大型溞比未接触过的大型溞更有效地躲避了鲷的攻击。识别来自碾碎同种个体的信号在遭遇不熟悉的捕食者以及食性发生个体发育转变的捕食者时可能具有特别的适应性。在自然条件下，这种信号与捕食者信号的组合能够非常可靠地表明捕食影响的局部范围。
